1. Field of the Invention
The present invention relates to a poke-through wiring device and, more particularly, pertains to a self-anchoring flush-type poke-through electrical wiring fitting which is adapted to be positioned in a floor aperture which is formed in a concrete building floor, for enabling the conducting of electrical power and telecommunication signals between the work spaces of multi-storied buildings.
Basically, during the erection of various types of building structures; for instance, especially such as modern multi-storied office buildings possessing concrete floors, it is frequently necessary, and also commonly accepted building practice, to normally provide fire-rated poke-through fittings and devices for conducting insulated conductors, wires, cables and the like for the transmission of electrical power and telecommunication signals through suitable holes or apertures which are formed in the concrete building floors. Hereby, this enables electrical power and other kinds of signals, such as telecommunication signals, to be readily transmitted from a suitable source; for instance, from a junction box located at or proximate one face, ordinarily the lower surface of the concrete floor through the intermediary of the poke-through fitting through the aperture in the concrete building floor to a suitable outlet or service head which is located at the opposite, generally upper face of the floor. Thus, in order to accomplish the foregoing purpose; essentially, the positioning in a floor aperture of a poke-through wiring device or fitting of the type described herein, the service head, under various circumstances, is intended to incorporate a carpet flange which is to be mounted flush on the upper surface of the floor or on a carpet which covers the floor; and in which the device may be equipped with suitable gripping structure enabling the poke-through wiring device or fitting to be inserted from above into the floor aperture formed in a concrete floor so as to resultingly anchor itself in a predetermined orientation in the aperture, inhibiting withdrawal of the fitting therefrom, while suspending a junction box below the floor aperture, as may be required.
Heretofore, under various circumstances, the poke-through wiring fitting, which generally incorporates fire barrier structure, usually intumescent-material discs, adapted to be located within the confines of the floor aperture, at the end thereof opposite the floor surface mounting the service head, incorporated a suitable toggle arrangement proximate the junction box for clamping engagement with the lower surface of the concrete floor, so as to enable the fitting to be anchored in the floor aperture. Such a toggle arrangement generally included plate members having axially oriented screw members threadingly extending therethrough oriented coextensive with the axial alignment of the fitting, and which contact against the lower surface of the concrete floor structure so as to draw the poke-through wiring fitting downwardly into a flush-mounted engagement at the upper end thereof with the opposite surface of the floor.
Various types and designs of floor fittings of this kind eliminate the need for such toggle arrangements by providing for clip-like anchoring or gripping structure as a component of the poke-through fitting, which structure normally biasingly engages the circumferential wall surface of the floor aperture in order to firmly anchor and secure against withdrawal of the poke-through fitting in predetermined axially and/or radially adjusted positions within the floor aperture. In essence, as a consequence of eliminating the toggle arrangement, this imparts the poke-through wiring device or fitting with the capability of being introduced into the floor aperture from above and enabling it to be anchored in a predetermined oriented position within the floor aperture while eliminating the need for the services of cooperating electricians having to work in tandem on the floors above and below the floor aperture in order to obtain an appropriately oriented installation of the poke-through fitting; in effect, permitting the work to be carried out by a single unaided electrician or installer, thereby significantly reducing attendant labor costs.
Although numerous type of structures have been heretofore proposed and are currently in widespread use in this technology for the purpose of anchoring poke-through wiring devices or fittings in concrete floor apertures, not all of these structures have been able to completely satisfactorily meet the requirements in being able to not only anchor the poke-through fitting in the floor aperture through the intermediary of a novel clip structure, but also impart a capability to the upper end portion of the fitting of mounting a detachable installation plate which is to be employed as a template for the cutting and laying of floor carpeting about the floor aperture and to thereafter enable the replacement of the installation plate with a suitable carpet flange and receptacle assembly, and by application of foot pressure downwardly to the carpet flange, push the poke-through fitting downwardly into the floor aperture into its final flush-mounted anchored position.
2. Discussion of the Prior Art
At this time, various types of anchoring devices are known to provide for the self-anchoring of poke-through wiring fittings in floor apertures of multi-storied buildings, and all of which effectively eliminate the need for so-called toggle assemblies for clamping the poke-through wiring devices or fittings in position generally through the employment of spring clips which engage the wall structure of the floor apertures.
In order to provide for the self-anchoring of the poke-through fittings or wiring devices or fitting in the floor apertures it has heretofore been contemplated, pursuant to a specific instance, to compress fire-resistant discs, such as are ordinarily made of an intumescent material, between two metal plates in a sandwich structure, and to thereby squeeze the intumescent discs so as to cause them to expand radially outwardly into contact with the perimeter of an aperture wall in a concrete floor to thereby securely retain the fittings therein. Although that type of structure imparts a self-anchoring feature to the fittings, it does not facilitate orienting the wiring fittings in their appropriate angular positions so as to enable installing the wiring devices or poke-through fittings in the floor apertures without the need for cooperating electricians working on opposite building floors. Devices of that type are described, for example, in Carroll, et al. U.S. Pat. No. 4,272,643.
An anchoring structure for poke-through wiring devices or fittings of the general type considered herein is set forth in shine U.S. Pat. No. 4,323,724, in which, fastened to a fire-retarding intumescent disc assembly, a split notched, ring-shaped resilient dished spring washer has anchoring surfaces adapted be wedged against the perimeter wall surface of a concrete floor aperture so as to securely anchor in the entire poke-through wiring device or fitting therein in a predetermined angular orientation relative to the axis of the aperture. Although the fitting as elucidated in this patent publication imparts an essentially adequate self-anchoring feature to the poke-through fitting, in order to be able to remove the fitting from its installed position in the concrete floor aperture, this necessitates the entire fitting having to be forcibly pulled out, thereby practically either completely destroying or seriously damaging structural components thereof, necessitating expensive replacement thereof, in addition to entailing high labor costs in installing a new poke-through fitting.
Another structure for the anchoring of a poke-through wiring device or fitting in a concrete floor aperture is described in Spencer U.S. Pat. No. 4,496,790, wherein a pair of substantially diametrically oppositely arranged resilient clips protrude beyond the diameter of a fire retarding plate-sandwich structure of a poke-through fitting on which they are mounted by means of screw fasteners so as to contact, in a gripping manner, the perimeter of an aperture wall formed in a building floor which is constituted of a concrete material, thereby enabling the device to anchor itself in a predetermined angular orientation upon insertion therein, while facilitating removal and repositioning of the fitting through loosening of the screw fasteners and, resultingly, of the clips.
However, although the foregoing anchoring structure incorporating resilient clips improves upon the structure described in Shine U.S. Pat. No. 4,323,724 by enabling the clips to be removed through the loosening of the screw fasteners, and enabling the repositioning of the fitting subsequent to its being withdrawn from the floor aperture, the utilization of resilient clips which are of an essentially V-shaped configuration and in which the freely-flexible clip leg portion of the V-shape contacts the concrete wall fails to provide for an adequate gripping engagement with the wall of the concrete floor aperture, since the considerable flexibility and delicate nature inherent to this particular clip design does not allow for the exertion of a strong radial gripping force to be produced by this anchoring structure of the poke-through wiring device.
A poke-through connector assembly incorporating a resilient spring clip which is attached to the lower surface of a basket containing intumescent material is disclosed in Bloom U.S. Pat. No. 5,032,690, wherein the material expands to fill the aperture when the floor is subjected to fire and heat, and in which the spring clip resiliently engages the wall surface of the floor aperture through the intermediary of radially outwardly extending prong members so as to essentially anchor the poke-through fitting in the aperture. However, this resilient type of clip structure does not provide for the necessarily firm anchoring action which will inherently prevent any displacement of the fitting when the upper end thereof, which may consist of a carpet flange or the like service head structure, is subjected to rough handling.
Finally, Castellani, et al. U.S. Pat. No. 4,770,643 provides for a retaining member which is essentially of a disc-shape and is attached to the lower surface of intumescent material discs and support plate structure and which provides for circumferentially spaced prongs of a plate-like clip member of an inherently resilient nature engaging the wall surface of the floor aperture. Although this provides for an anchoring effect for the poke-through wiring fitting, there is no force of sufficient magnitude being exerted by the prongs against the wall surface of the floor aperture to securely prevent rotational or upward axial displacement of the wiring fitting.